1. Technical Field The present invention relates to a method of manufacturing an ink-jet head.
2. Description of the Related Art
Ink-jet printers can perform printing by converting an electrical signal to a physical force and ejecting ink droplets through a nozzle. An ink-jet head can be manufactured by processing various components such as a chamber, a restrictor, a nozzle, a piezoelectronic element, etc., on corresponding layers and bonding the layers with one another.
Recently, the ink-jet head is increasingly used not only in the conventional graphic ink-jet industry for printing on paper or fabric but also in the manufacture of electronic components, for example, a printed substrate and an LCD panel, etc.
As a result, the ink-jet printing technology for an electronic component that needs to discharge functional ink more correctly and precisely than the conventional graphic printing method requires functions that have not been required for the conventional ink-jet head. While the basic requirements stipulate the size and speed variation of discharged ink droplets, high density nozzles and high-frequency characteristics are also required for higher production.
In order to meet such requirements, the performance of a piezoelectric element, which is an actuator of the ink-jet head, needs to be improved urgently. In one of the methods of manufacturing the actuator of the ink-jet head, a powder-like piezoelectric element is mixed with a polymer binder at a certain ratio on a pre-sintered ceramic vibration plate to have viscosity, and then screen-printed, patterned and co-fired. In another method, the piezoelectric element is sintered after the piezoelectric element is patterned through the screen printing method, etc. on a vibration plate made of a material having a melting point higher than the sintering temperature of the piezoelectric element.
The actuator manufactured by the methods described above may have a deteriorated performance due to, for example, a defective pin hole inside the material and may be electrically disconnected when forming an upper and lower electrodes.
Additionally, such methods make it difficult to process the piezoelectric element functioning as an actuator to have a thickness of less than 100 um and cause the outer shape of the piezoelectric element to collapse. It is also difficult to align the piezoelectric element when bonding the piezoelectric element.